Objective - C的連接測試警告

Question

我有以下代碼：

//View guest list 
-(IBAction) guestList:(id) sender{ 
    NSString *connected = [NSString stringWithContentsOfURL:[NSURL URLWithString:@"myURL"]]; 

    //Waits a set peroid of time 
    wait(20000); 

    //Guest list is availible 
    if (connected != NULL){ 
     CHARLIEAppDelegate *appDelegate = [[UIApplication sharedApplication] delegate]; 
     [appDelegate displayView:6]; 
    } 
    //No network connection availible 
    else { 
     UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"No Network Connection!" message:@"Cannot establish internet connection." delegate:self cancelButtonTitle:@"OK" otherButtonTitles: nil]; 
     [alert show]; 
     [alert release]; 
    } 

} 

而且我得到以下警告：

//Waits a set peroid of time 
    wait(20000); 

給我 - 警告：傳遞的參數1 '等待' 品牌從整數指針不進行強制轉換

NSString *connected = [NSString stringWithContentsOfURL:[NSURL URLWithString:@"http://photostiubhart.comoj.com/testconnection.php"]]; 

給我 -

警告： 'stringWithContentsOfURL：' 被棄用（在/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator4.3.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSString.h聲明：384）

我做了我的測試和代碼SEEMS工作正常，即使有這些警告。有沒有辦法根本去除這些警告？或者他們不重要？

我使用的Xcode 3.2.6以上版本

感謝，

傑克

Answer 1

使用

NSError* error; 
NSString* connected = [NSString stringWithContentsOfURL:TheUrl encoding:NSASCIIStringEncoding error:&error]; 

Answer 2

您應該使用方法 -

+(id)stringWithContentsOfURL:(NSURL *)url encoding:(NSStringEncoding)enc error:(NSError **)error 

爲例子 -

NSString* text = [NSString stringWithContentsOfURL:TheUrl encoding:NSASCIIStringEncoding error:&error]; 

希望它能幫助你。

Answer 3

嘗試做這種方式：

-(IBAction)guestList:(id) sender{ 
    NSURL *requestUrl = [NSURL URLWithString:@"http://photostiubhart.comoj.com/testconnection.php"]; 
    NSURLRequest *requestObj = [NSURLRequest requestWithURL:requestUrl]; 
    NSData *loadTest = [NSData dataWithContentsOfURL:requestUrl]; 

    if (loadTest == nil) { 
     UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"No Network Connection!" message:@"Cannot establish internet connection." delegate:self cancelButtonTitle:@"OK" otherButtonTitles: nil]; 
     [alert show]; 
     [alert release]; 
    } else { 
     CHARLIEAppDelegate *appDelegate = [[UIApplication sharedApplication] delegate]; 
     [appDelegate displayView:6]; 
    } 
}